What is defined as the separation between conditioned space and unconditioned space in buildings?

The concept of the building envelope is crucial in understanding the separation between conditioned and unconditioned spaces in buildings. The building envelope includes all the components that separate the interior environment of a structure—where heating, cooling, and humidity control occur—from the external environment. This encompasses walls, roofs, windows, doors, and foundations, all of which work together to maintain indoor temperatures and air quality.

A properly defined building envelope can significantly impact the energy efficiency of a home, as it helps to prevent unwanted heat transfer, moisture intrusion, and air leaks. By effectively delineating conditioned spaces (like living rooms, bedrooms, or offices) from unconditioned areas (such as attics, basements, or garages), the building envelope plays a pivotal role in energy consumption, comfort, and durability of the home.

While the roof, foundation, and exterior walls contribute to the building envelope, they do not comprehensively define the separation themselves. It is the entirety of the building envelope that establishes this important boundary in building construction and design.